The
current national census is currently in progress since 2020; the next census is scheduled for 2030. Since 2013, the Census Bureau began discussions on using technology to aid data collection starting with the 2020 Census.[2] In 2020, every household will receive an invitation to complete the census over the internet, by phone or by paper questionnaire.[3][4]
For years between the decennial censuses, the Census Bureau issues estimates made using surveys and statistical models, in particular, the
Population Estimates Program and
American Community Survey.

Procedure

A woman with a Hollerith pantograph punch, the keyboard is for the 1920 US Census population card

This
1940 Census publicity photo shows a census worker in Fairbanks, Alaska. The dog musher remains out of earshot to maintain confidentiality.

Decennial U.S. Census figures are based on actual counts of persons dwelling in U.S. residential structures. They include citizens, non-citizen legal residents, non-citizen long-term visitors and illegal immigrants. The Census Bureau bases its decision about whom to count on the concept of usual residence. Usual residence, a principle established by the Census Act of 1790, is defined as the place a person lives and sleeps most of the time. The Census Bureau uses special procedures to ensure that those without conventional housing are counted; however, data from these operations are not considered to be as accurate as data obtained from traditional procedures.[5]

In instances where the Bureau is unsure of the number of residents at an address after a field visit, its population characteristics are inferred from its nearest similar neighbor (hot-deck
imputation). This practice has effects across many areas, but is seen by some as controversial.[6] However, the practice was ruled constitutional by the
U.S. Supreme Court in Utah v. Evans.

Certain American citizens living overseas are specifically excluded from being counted in the census even though they may vote. Only Americans living abroad who are “Federal employees (military and civilian) and their dependents living overseas with them” are counted. “Private U.S. citizens living abroad who are not affiliated with the Federal government (either as employees or their dependents) will not be included in the overseas counts. These overseas counts are used solely for
reapportioning seats in the U.S. House of Representatives”.[7]

According to the Census Bureau, “Census Day” has been April 1 since 1930. Previously, from 1790 to 1820, the census counted the population as of the first Monday in August. It moved to June in 1830, (June 2 in 1890), April 15 in 1910, and January 1 in 1920.[8]

Controversy

This section needs to be updated. Please update this article to reflect recent events or newly available information.(August 2019)

The Census Bureau estimates that in 1970 over six percent of African Americans went uncounted, whereas only around two percent of European Americans[9] went uncounted. Democrats often argue that modern sampling techniques should be used so that more accurate and complete data can be inferred. Republicans often argue against such sampling techniques, stating the U.S. Constitution requires an “actual enumeration” for apportionment of House seats, and that political appointees would be tempted to manipulate the sampling formulas.[10]

Groups like the
Prison Policy Initiative assert that the census practice of counting prisoners as residents of prisons, not their pre-incarceration addresses, leads to misleading information about racial demographics and population numbers.[11]

In 2010 Jaime Grant, then director of the
National Gay and Lesbian Task Force's Policy Institute, thought of the idea of a bright pink sticker for people to stick on their census envelope which had a form for them to check a box for either “lesbian, gay, bisexual, transgender or straight ally,” which her group called “queering the census”.[12] Although the sticker was unofficial and the results were not added to the census, she and others hope the 2020 census will include such statistics.[12] In 2015
Laverne Cox called for transgender people to be counted in the census.[13]

2018-2019 Citizenship question controversy

On March 26, 2018 the U.S. Dept of Commerce announced[14] plans to re-include a citizenship question in the 2020 census questionnaire which has not been included on the short form since 1950.[15] The Census Bureau distributed a “long form” to a sample of households receiving the standard Census form in three Censuses from 1970 to 2000,[16] which included a question on citizenship.[17] The proposed citizenship question will be the same as the one that is asked on the yearly
American Community Survey (ACS), which is answered by a sample of US households.[14][18]

Proponents of including the question claimed it is necessary to gather an accurate statistical count, while opponents claimed it might suppress responses to the Decennial Census and therefore lead to an inaccurate count.[19] Multiple states have sued the Trump administration arguing that the proposed citizenship question is unconstitutional and may intimidate illegal aliens and undocumented workers, resulting in inaccurate data on immigrant communities.[20] In January 2019 a federal judge in New York ruled against the proposal; the U.S. Government appealed that decision to the U.S. Supreme Court which heard oral arguments in April 2019 about whether the citizenship question was constitutional and whether the Secretary of Commerce followed the law when deciding to add the question. The Supreme Court issued its decision on June 27, 2019, rejecting the Trump administration's stated rationale for including the question.[21] As a result, the 2020 Census does not include a question on citizenship. On July 11, 2019, President Trump issued an executive order directing the Department of Commerce to obtain citizenship data from other federal agencies rather than via the census.[22]

History

Censuses had been taken prior to the Constitution's ratification; in the early 17th century, a census was taken in
Virginia, and people were counted in almost all of the British colonies that became the
United States.

Throughout the years, the country's needs and interests became more complicated. This meant that statistics were needed to help people understand what was happening and have a basis for planning. The content of the decennial census changed accordingly. In 1810, the first inquiry on manufactures, quantity and value of products occurred; in 1840, inquiries on fisheries were added; and in 1850, the census included inquiries on social issues, such as taxation, churches, pauperism, and crime. The censuses also spread geographically, to new states and territories added to the Union, as well as to other areas under U.S. sovereignty or jurisdiction. There were so many more inquiries of all kinds in the census of 1880 that almost a full decade was needed to publish all the results. In response to this, the census was mechanized in 1890, with
tabulating machines made by
Herman Hollerith. This reduced the processing time to two and a half years.[23]

For the first six censuses (1790–1840), enumerators recorded only the names of the heads of household and a general demographic accounting of the remaining members of the household. Beginning in 1850, all members of the household were named on the census. The first slave schedules were also completed in 1850, with the second (and last) in 1860. Censuses of the late 19th century also included agricultural and industrial schedules to gauge the productivity of the nation's economy. Mortality schedules (taken between 1850 and 1880) captured a snapshot of life spans and causes of death throughout the country.

The first nine censuses (1790–1870) were conducted by U.S. Marshals before the Census Bureau was created.[24] Appointed US Marshals of each judicial district hired assistant marshals to conduct the actual enumeration. The census enumerators were typically from the village or neighbourhood and often knew the residents. Before enabling self-identification on the censuses, the US Census Bureau relied on local people to have some knowledge of residents. Racial classification was made by the census enumerator in these decades, rather than by the individual.

The 1850 census was a landmark year in American census-taking. It was the first year in which the census bureau attempted to record every member of every household, including women, children and slaves. Accordingly, the first slave schedules were produced in 1850. Prior to 1850, census records had only recorded the name of the head of the household and tabulated the other household members within given age groups.

The results were tabulated by 184 clerks in the Bureau of the Census. This was the first census where the American Indians officially were counted, but only those who had 'renounced tribal rules'. The figure for the nation was 40,000.

The first census to provide detailed information on the black population, only years after the culmination of the Civil War when slaves were granted freedom. The results are controversial, as many believed it underestimated the true population numbers, especially in New York and Pennsylvania.

Because it was believed that the frontier region of the United States no longer existed, the tracking of westward migration was not tabulated in the 1890 census.[25] This trend prompted
Frederick Jackson Turner to develop his milestone
Frontier Thesis.

The 1890 census was the first to be compiled using the new
tabulating machines invented by
Herman Hollerith. The net effect of the many changes from the 1880 census (the larger population, the number of data items to be collected, the Census Bureau headcount, the volume of scheduled publications, and the use of Hollerith's electromechanical tabulators) was to reduce the time required to fully process the census from eight years for the
1880 census to six years for the 1890 census.[26] The total population, of 62,947,714, was announced after only six weeks of processing (punched cards were not used for this family, or rough, count).[27][28] The public reaction to this tabulation was disbelief, as it was widely believed that the "right answer" was at least 75,000,000.[29]
This census is also notable for the fact it is one of only three for which the original data are no longer available. Almost all the population schedules were destroyed following a fire in 1921.

The first short-form-only census since 1940, as the decennial long form has been replaced by the
American Community Survey. The first census that recorded a population exceeding 300 million. Will be available for public inspection on April 1, 2082.

Respondent confidentiality

One purpose of the census is to divide the house seats by population. Furthermore, as with any Census Bureau survey the data provides a beginning for allocation of resources. In addition, collected data are used in aggregate for statistical purposes.[30] Replies are obtained from individuals and establishments only to enable the compilation of such general statistics. The confidentiality of these replies is very important. By law, no one—neither the census takers nor any other Census Bureau employee—is permitted to reveal identifiable information about any person, household, or business.

By law (
Pub.L.95–416, 92
Stat.915, enacted October 5, 1978), individual decennial census records are sealed for 72 years,[31] a number chosen in 1952[32] as slightly higher than the average female life expectancy, 71.6.[33] The individual census data most recently released to the public is the 1940 census, released on April 2, 2012. Aggregate census data are released when available.

In 1980, four FBI agents went to the Census Bureau's
Colorado Springs office with
warrants to seize Census documents, but were forced to leave with nothing. Courts upheld that no agency, including the FBI, has access to Census data.[36]

Data analysis

The census records data specific to individual respondents are not available to the public until 72 years after a given census was taken, but aggregate statistical data derived from the census are released as soon as they are available. Every census up to and including
1940 is currently available to the public and can be viewed on
microfilm released by the
National Archives and Records Administration, the official keeper of archived federal census records. Complete online census records can be accessed for no cost from National Archives facilities and many libraries,[37] and a growing portion of the census is freely available from non-commercial online sources.[38][39][40]

Census
microdata for research purposes are available for censuses from
1850 forward through the Integrated Public Use Microdata Series (
IPUMS), and scanned copies of each of the decennial census questionnaires are available online from many websites. Computerized
aggregate data describing the characteristics of small geographic areas for the entire period from
1790 to
2010 are available from the
National Historical Geographic Information System.

Regions and divisions

US Census Bureau Population Regions

The bureau recognizes four census
regions within the United States and further organizes them into nine divisions. These regions are groupings of states that subdivide the United States for the presentation of data. They should not be construed as necessarily being thus grouped owing to any geographical, historical, or cultural bonds.

Notes

^At the time of the 1800 Census, the territory donated to form the District of Columbia was still being administered by the states of Maryland and Virginia. The state of Maryland included the population of the District under its control within its own return. The population of the District of Columbia within Maryland was 8,144 persons, including 5,672 whites, 400 free blacks, and 2,472 enslaved persons.

^Porter, Robert; Gannett, Henry; Hunt, William (1895). "Progress of the Nation", in "Report on Population of the United States at the Eleventh Census: 1890, Part 1". Bureau of the Census. pp. xviii–xxxiv.

^Report of the Commissioner of Labor In Charge of The Eleventh Census to the Secretary of the Interior for the Fiscal Year Ending June 30, 1895. Washington, DC:
United States Government Publishing Office. July 29, 1895.
hdl:
2027/osu.32435067619882.
OCLC867910652. p. 9: "You may confidently look for the rapid reduction of the force of this office after the 1st of October, and the entire cessation of clerical work during the present calendar year. ... The condition of the work of the Census Division and the condition of the final reports show clearly that the work of the Eleventh Census will be completed at least two years earlier than was the work of the Tenth Census." — Carroll D. Wright, Commissioner of Labor in Charge